Wednesday, March 5, 2008

Coronary bypass surgery effective but high-risk procedure for cardiogenic shock patients
By Kelly Winget

A potential complication from an acute heart attack is that a patient will develop cardiogenic shock, which can greatly increase a patient's risk of death. A new study, led by DCRI researchers, found that although coronary artery bypass grafting (CABG) surgery can be risky for these patients, it can still be effective if other techniques are incorporated into the surgery.

Cardiogenic shock (CS) is when the heart is damaged badly enough following a heart attack that the blood flow in the body decreases suddenly, and the blood cannot return to the heart for it to function properly. Although it is common in heart attack patients, there have not been many large studies to date on outcomes of CS patients who undergo CABG surgery.

Researchers analyzed data from the Society of Thoracic Surgeons National Cardiac Database on more than 708,000 patients who had CABG surgery between 2002 and 2005. Only 2 percent of patients were in cardiogenic shock before surgery, but accounted for 14 percent of deaths related to CABG surgery.

Study results were published in the February 19 issue of Circulation.

Although the patients who had CS were close in age to those patients who were not in shock, they typically had more co-existing medical conditions and a much higher percent had suffered an acute heart attack within 24 hours before having CABG surgery.

The CS patients who had CABG surgery typically had longer hospital stays and required more time in an intensive care unit than patients who did not have CS. The patients with CS accounted for approximately one in seven deaths among patients who had CABG surgery.

Despite the risks, researchers noted that CABG offers a number of benefits to CS patients, including a more complete revascularization than other surgeries would provide. The study provides a tool to help physicians better predict which patients have greater risk of death or major complications. For appropriately selected CS patients, 70 percent of patients survived the surgery, even among patients 75 years and older.

"It is reasonable for clinicians to consider surgical options in appropriate functional elderly patients with cardiogenic shock,” the researchers said in the report.

One way physicians could help improve outcomes for CS patients would be to increase the use of intra-aortic balloon pumps prior to surgery, according to the study.

DCRI researchers included Rajendra H. Mehta, MD, MS; Joshua D. Grab, MS; Sean M. O'Brien, PhD and Eric D. Peterson, MD, MPH.